Apparatus for the generation of steam



Nov. 3, 1936. o. HARTMANN APPARATUS FOR THE GENERATION OF STEAM Filed June 25, 1935 2 Sheets-Sheet 1 lnvemor OH 0 Hart mann A tomgys Nov. 3, 1936. o. HARTMANN APPARATUS FOR THE GENERATION OF STEAM Filed June 25, 1935 2 Sheets-Sheet 2 //7 ventol:

Otto Hartmann A ttomeys Patented Nov. 3, 1936 UNITED}. STATES PATENT' OFFICE APPARATUS FOR THE GENERATION OF STEAM- many Application June 25, 1935, Serial No. 28,370.

In Germany June 28, 1934 4 Claims.

The invention relates to a process and apparatus for the indirect generation of steam or other vapors, using a closed circuit for the heating medium.

In the usual indirectly heated steam generator, the heating medium is heated in one part of a closed circuit and then passes to a different part of the, circuit where it gives up its heat to the liquid to be vaporized. In the present invention, on the. contrary, heat from an outside source is supplied to the circulating heating medium both at other points and also in that part of the circuit in which the heating medium gives up its heat; or, in other words, while the heating medium is in heat exchange relation with the liquid to be heated.

More specifically, that portion of the closed circuit in which'the heating medium passes in heat exchange relation with the liquid to be vaporized is arrangedin the path of the flue gases so as to take up heat therefrom. The preferred arrangement consists in locating double Walled tubes in the flue, the heating medium passing through the outer space within the tubes and the liquid to be vaporized passing through the inner space.

There are many advantages in such a construe tion. Since the heat radiating portion of the closed circuit (that is, that portion in which the heating medium gives up its heat to the liquid to be vaporized) is used both to give ofi? heat and also to absorb heat,.the heating and radiating.

surfaces of the closed circuit may be 'made smaller for a boiler or generator of the same efficiency. .This is true since, where some of the heat is supplied to the same section which is radiating heat to the liquid to be vaporized, that much less heat need be applied to the other portions of the closed circuit, and these portions can therefore be made smaller for a generator having a given efliciency.

Furthermore, the heating elements which serve for the indirect transmission of heat to the liquid to be vaporized do not require a heavy boiler casing, for their support, but maybe subdivided into a plurality of heat absorbing heating surfaces. The weight of the boiler may thus be considerably reduced.

Further objects and advantages of the invention will be more fully apparent from the following description, particularly when taken in conjunction with the accompanying drawings which form a part thereof.

In the drawings:

Fig. 1 is a vertical section through a steam.

generator, particularly intended for use in vehicles, embodying the invention.

Fig. 2 is an enlarged cross section on the line II-II of Fig. 1.

Fig. 3 is a'detail side elevation, partly in section, of a portion of the arrangement shown in Fig. 1.

Fig. 4 is'a plan view, partly in section, of the portion of the apparatus shown in Fig. 3.

The vaporizing tubes, which form, as usual, the heat absorbing portion of the closed circuit in which the circulating heating medium is heated and vaporized, are so arranged as to form and enclose a combustion chamber, preferably rectangular in cross section. The tubes are connected to a lower'ring header I. The vertical vaporizing tubes 2, arranged to form." the side.

walls of the combustion chamber, are all connected at their upper ends to a header 3, the front end of this header being connected to a cylinder 4. Vaporizing tubes 5, for the front Wall, extend about half way up the front wall of the combustion chamber and are then bent inwardly (or rearwardly) across the chamber above the fire box, and then are. again bent forwardly and connected with cylinder 4. The vaporizing tubes 6 forming the back wall of the combustion cham-v ber are bent forwardly at their upper ends and connected with cylinder 4. The portions of the tubes 5 and 6 above the combustion chamber are staggered so as to provide spaces therebetween for the escape of the flue or combustion gases.

A superheater 1, shown merely diagrammati cally, is arranged above the tubes 5 and 6. Above the superheater are arranged tubes 8, extending substantially parallel to tubes 5 and 6, the arrangement and construction of which will be de.

scribed below. Baflies 9, I0, and I2 are arranged between and around the tubes 5, 6, and B and the superheater 1 in such a manner as to cause the combustion or flue gases from the combustion chamber to flow in a zig-zag path, as indicated by the arrows a (Fig. 1), to a flue outlet [3. The passages formed by the baffles 9, l0, and I2 thus constitute a fine or flue space through which the gases will escape from the combustion chamber. During such passage, as is obvious, these flue gases pass in contact with the tubes 5, 6, B and superheater 1.

Cylinder 4 is connected by descendingtubes M to the ring header I, the lower portions of these descending tubes being protected from the heat of the combustion chamber by the tubes 5, and the upper section by a suitable wall l5 of refractory material.

The tubes 8 form casings or outer walls, through which pass smaller tubes I6 which are longer than and extend beyond the ends of the tubes 8. The tubes 8 are closed at their ends by collars H, the ends of the tubes being bent inwardly around the collars and welded to the inner tubes [5 (Fig. 3). The inner tubes are each welded or otherwise suitably secured at one end in a steam drum or cylinder [8. This cylinder is provided with openings adapted to be closed by plugs I9, through which openings the tubes I 6 may be suitably cleaned. These plugs are preferably arranged in the wall of the cylinder l8 opposite the ends of the tubes I6. The other or rear ends of the tubes l6 are each connected to a vertical chamber or header 2!). A plurality of these headers are provided to receive a plurality of vertically arranged rows of tubes. Headers 20 at their lower ends are connected to a header 2|, which in turn is connected by pipes 22 to drum l8.

The heating steam generated in the heat absorbing portion of the closed circuit passes to cylinder 4, where it separates from the water and flows through passage 23 to the outer chambers 24 of tubes 8. The spaces 24 within the tubes 8 are connected together at the front end by means of nipples 25 and at the rear end by nipples 26. Return tubes 2'! extend from the rear end of the lowermost of each series of tubes 8 to the ring header I. These tubes 27 are protected from the heat of the combustion chamber by the vertical parts of vaporizing tubes 6.

The steam generated in the inner tubes 56 passes to the drum l8 and is carried off from this drum through tube 28 and superheater l to its point of use.

It is believed that the operation of the device will be evident. The heating medium heated in the tubes 2, 5, and 6 passes to cylinder 4, the steam thus produced passing to the outer spaces 24 of tubes 8. As this steam flows through tubes 8, it is in heat exchange relation with the liquid to be vaporized in the inner tubes I6, and gives up its heat to the liquid. At the same time, however, the flue gases from the combustion chamber are passing in contact with the outside of tubes 8 which are arranged in the flue, and thus in heat exchange relation with the heating medium vapors within the tubes 8. The heating medium condensed in the tubes 8 then passes downwardly through tubes 21 to complete the circuit.

The ratio of the heating surfaces is preferably so calculated, with respect to the temperatures which occur during the operation of the apparatus, that the heating medium will condense within the annular spaces 24 of the tubes 8. This may be accomplished where necessary by suitable variation of the shape of the surfaces of the inner tubes so that they will take up the heat more quickly from the heating medium. This produces transmission of heat to the liquid to be vaporized in the inner tubes I 5, from which the steam is generated for use, under very favorable and efficient conditions.

While I have described herein one embodiment of my invention, I wish it to be understood that I do not intend to limit myself thereby except within the scope of the appended claims,

I claim:

1. In a. vapor generator, a combustion chamber, a closed circuit for a heating medium having portions located within said chamber to be heated by combustion therein, a flue connected to said chamber for carrying off combustion gases therefrom, said circuit further including tubes located in said flue, and other tubes within said first tubes for conducting a liquid to be vaporized in heat exchange with the heating medium in the first tubes, a drum for the liquid to be vaporized, a plurality of vertical headers, means connecting said headers to said drum, said second tubes being connected at their ends to said headers and said drum respectively, whereby the medium in said first tubes simultaneously gives up heat to the liquid to be vaporized and receives heat from the combustion gases in said flue.

2. In a vapor generator, a combustion chamber, a closed circuit for a heating medium having portions located within said chamber to be heated by combustion therein, a flue connected to said chamber for carrying ofif combustion gases therefrom, said circuit further including a plurality of tubes arranged one above the other in said flue, means connecting said tubes together at both ends thereof, and other tubes within said first tubes for conducting a liquid to be vaporized in heat exchange with the heating medium in the first tubes, a drum for the liquid to be vaporized, a plurality of vertical headers, means connecting said headers to said drum, said second tubes being connected at their ends to said headers and said drum respectively, whereby the medium in said first tubes simultaneously gives up heat to the liquid to be vaporized and receives heat from the combustion gases in said flue.

3. In a vapor generator, a closed circuit for a heating medium, said circuit including a tube system for guiding the medium in its circulating movement, a drum for the liquid to be vaporized, a circulating system connected at both ends to said drum for conducting the liquid to be vaporized from said drum into heat exchange relation with the heating medium and returning the same to the drum, means to heat the portion of the heating medium which is in heat exchange relation with the liquid to be vaporized while it is giving up heat to the liquid, said tube system and circulating system lying entirely outside said drum.

4. In a vapor generator, a closed circuit for a heating medium, said circuit including a tube system for guiding the medium in its circulating movement, a drum for the liquid to be vaporized, a circulating system connected at both ends to said drum for conducting the liquid to be vaporized from said drum into heat exchange relation with the heating medium in a part of its closed circuit and returning the same to the drum, means to heat the portion of the heating medium in said part of the closed circuit which is in heat exchange relation with the liquid to be vaporized while it is giving up heat to the liquid, said tube system and circulating system lying entirely outside said drum.

OTTO HARTMANN. 

